Lesson 18:Octave Transposition

To transpose music means to change the pitch of each note without changing the relationships between the notes. This usually means changing the key. However, in this lesson, we will study transposition by one octave. Transposing a melody up or down by one octave will not change the key. (Key transposition will be studied in a later lesson.) Look at the following melody:

   

The first note of this melody is 'F'. If we count upward eight notes (one octave), we reach 'F' again.

Because you studied Lesson 16 (Key Identification), you know that this excerpt is in F-major. When transposing a melody up one octave, the key stays the same (in this example, F-major).

All of the note names stay the same, but they are now an octave higher. Therefore, all of the pitch relationships stay the same: the highest note in this melody is 'G' (the supertonic note); the lowest note is 'C' (the dominant note), etc.

Here is the same melody transposed down one octave:

As you can see, it doesn't fit on the treble clef too well: it is now too low. The performer would be required to read several leger lines. Although this is allowable, it is better to change to the bass clef:

Now it fits on the staff better. It's at the same starting pitch as the previous example:

When asked to transpose music up or down by one octave, there are some things you will want to keep in mind:

• Make sure to check the stem direction: unbeamed notes above the middle line have stems down, unbeamed notes below the middle line have stems up. For beamed notes, find the note in the beamed group that is the furthest away from the middle line; the stems should go in the direction appropriate for that note.
• If you know the instrument that the transposed melody will be played on, make certain to use the proper clef, and ensure that the notes are within the range of that instrument. (This is beyond the scope of music theory, but it is an issue for music composers and arrangers.)

Here are some melodies and their octave transpositions. Study them carefully:

i) G-minor, treble clef.      Transposed up one octave:  

ii) A-major, treble clef.      Transposed down one octave:  

iii) D-major, bass clef:        Transposed up one octave into the treble clef:  

iv) B-flat major, treble clef:       Transposed down into the bass clef: